Using the textbook example of 420 California school districts and the regression of testscores on the student-teacher ratio, you find that the standard error on the slope coefficient is 0.51 when using the heteroskedasticity robust formula, while it is 0.48 when employing the homoskedasticity only formula. When calculating the t-statistic, the recommended procedure is to A. use the homoskedasticity only formula because the t-statistic becomes larger B. first test for homoskedasticity of the errors and then make a decision C. use the heteroskedasticity robust formula D. make a decision depending on how much different the estimate of the slope is under the two procedures

The answer is "Option C".

Step-by-step explanation:

Robust standard errors or generic White-Huber mistakes depending on this procedure. This is also recognized as the Variance Sandwich Stimator because of the appearance of the formula. Therefore, which is under homoskedasticity, robust error terms were appropriate, in which the standard deviations of its predictor variables are non-constant and are tracked across different values or linked to pre-time periods of an exponential function.

The answer is in the image 

For 1 flavor there are 9 topping

Therefore, for 5 different flavors there will be 5*9 choices

No of choices= 5*9

=45 

The total nom of  code that can be used is equal to 5+3 = 8

The answer is in the image 

y=2x+15

where y=Value of coin

x=Age in years

Value of coin after 19 years=2*19+15

=$53

Therefore, Value after 19 years=$53

The answer is in the image 

The answer is in the image 

Here,

tip=18%of $32

tip=(18/100)*32

=0.18*32

=$5.76

Total payment=32+5.76=$37.76

Speed=Distance/time

Here,

distance=15m

time=1sec

speed=15/1=15m/sec

Distance=Speed*time

time=15min=15*60sec=900sec

Distance travelled in 15 min=15*900=13,500m

=13500/1000 km=13.5Km